Frederick William was known as a brutal man because of his short temper, severity, and coarse manners. He was born at Oranienbaum Castle, and was educated and raised by his uncle, King Frederick I, and then by his cousin, King Frederick William I. His character closely resembled that of his second royal guardian, who like himself, hated idleness and was a terror to all loungers. The clergy were especial objects of his ridicule and persecution. His cane was as much feared as that of his royal namesake. He made the fashionable Grand Tour, travelling to Geneva 1715, and in 1716 to Italy. He returned in 1719 to Prussia, where he received the order of the Black Eagle from Frederick William I. On 15 June 1723 he was made a Prussian major-general. On 10 July 1737 he was appointed lieutenant-general. The existence of the Schwedt branch of the Hohenzollern dynasty, descended as they were from Frederick I's father and being 'princes of the blood', posed a theoretical threat to the Prussian kings. Frederick William I tried to neutralise this threat by keeping his cousins close, bringing the Schwedt brothers into his own household, acting as their guardian, and later marrying Frederick William to his daughter. Following the margrave's reaching adulthood the king was so fearful of any covert political activity on his cousin's part that he sent spies to Schwedt to find out who met with Frederick William and his brother. Margrave Frederick William pursued a lavish programme of building in Schwedt, both in the palace and town, and he actively purchased land and estates to augment his inheritance; this aggrandisement resulted in the king eventually forbidding him from making any more such purchases. In contrast to his father's policy Frederick II sought to distance himself from his Schwedt cousins, humiliating them at every chance. He made them unwelcome at his court, undermined the margrave's authority in his own dominions by encouraging complaints and lawsuits by his tenants and neighbours and, most effectively, he marginalised the position of the Schwedt brothers within the Prussian army. Margrave Frederick William was removed from command in the army, a denigration the king also extended to his own brothers. Frederick William was 19 years older than his wife Sophia Dorothea of Prussia, who was his first cousin once removed. The marriage, in 1734, was at the express wish of King Frederick William, against the wishes of his daughter; the bride was given away by her brother the future Frederick II, as the king was unwell. The relationship of the couple was not happy. Sophia often fled to the protection of her brother King Frederick. The latter did not stop at friendly admonitions, but sent General Meir to Schwedt with unlimited authority to protect the margravine from insult. Eventually they lived in separate places: Sophia lived in the castle Montplaisir, and the Margrave lived in the castle of Schwedt. Apparently they were only reconciled when the margravine was in her terminal illness; she died in her husband's arms. On 4 March 1771, Frederick William died at Wildenbruch Castle, when the heavy cold he was suffering from worsened. The Margrave acknowledged one illegitimate son, the only one of his male offspring to survive infancy. Due to his lack of surviving legitimate male issue, his lands and title were inherited by his younger brother Frederick Henry.
Issue
In 1734, the Margrave married Sophia Dorothea of Prussia and they had five children.
